In neighborhoods that 'we' often means the homeowner themselves. They are usually responsible for the 'public' sidewalk to the curb. The city and boroughs could offer incentives for repair but at $10k or more for a reasonable house's frontage, lots of folks are noping out of that.

I find that publicly or public service organization owned sidewalks are pretty reasonable - ramps and bump indicators at the intersections I think are all city so calling 311 can probably make some movement there. But I live in north Oakland: compare the sidewalks in front of little nippers and tamarind (and neighborhoods) to the high dollar ones outside Oakland Catholic, PNC bank, and the new cmu residence hall.